These beams were not shown to be the roof of the Temple itself.
Known. They are charred wooden beams from a building of the First Temple period.
The beams were found at the Givati Parking Lot dig, in the City of David, in Jerusalem. They were burned in 586 BC, when the Babylonians destroyed the First Temple, more than 2,600 years ago. The page says huge beams of sycamore wood seem to have roofed an inner courtyard. Melted plaster from a wall spread over the wood and sealed it. Well-preserved wood from a coniferous tree, with many growth rings, was also found in the same destruction layer. People later sealed off that part of the building and kept living in rooms that were not ruined.
The page does not say what is still argued.
https://www.ancient-origins.net/news-history-archaeology/first-temple-wooden-beams-found-00103012